A block copolymer refers to a copolymer consisting of a plurality of blocks or segments of repeating units with different characteristics from one another. It tends to be superior to typical random copolymers or polymer blends in its properties. For example, the block copolymer may comprise both of soft elastic blocks (referred to as “soft segments”) and hard crystalline blocks (referred to as “hard segments,”) and this makes it possible for the polymer to exhibit properties such as excellent elasticity and heat resistance, together. More specifically, such block copolymers may have elasticity at a temperature equal to or higher than the glass transition temperature of the soft segment and can have relatively good heat resistance because they do not show a thermoplastic behavior until they reach a temperature higher than their melting temperature.
Specific examples of the aforementioned block copolymer include triblock copolymer of styrene and butadiene (SBS) and its hydrogenated product, which have been known to find applications in many fields due to their superiority in heat resistance and elasticity.
Recently, olefin elastomers such as copolymers of α-olefins with ethylene or propylene have been intensively studied for their use. More specifically, many attempts have been reviewed to employ such olefin elastomers in various fields, for example, in different uses for substituting for rubber materials. In a bid to make improvements on heat resistance of the olefin elastomers, some attempts have also been made to adopt a block copolymer type elastomer in lieu of conventional random copolymer-based olefin elastomers (e.g., an ethylene-α-olefin random copolymer). Moreover, various approaches have come under review to prepare block copolymer type olefin elastomers with excellent processability through a simple process.